Paper-making typically involves forming, pressing, drying and reeling of a paper web passing through the paper machine. Current day paper-making machines operate at high speed and reel bars provided in the winding section of the machine must maintain an uninterrupted winding of the web onto the reel bar.
The reel bar contacts through nip engagement a driving drum and is driven by this engagement so that the paper web passing in contact with the driving drum is wound onto the reel bar. The reel bar usually is supported on rails during the reeling operation. Tension is provided to the web by running the driving drum faster than the speed of the previous section of the paper-making machine. The tension and nip pressure can be varied to produce rolls of paper with a desired tightness.
To maintain uninterrupted winding, a new reel bar is usually supported above the winding section of the machine as the paper is wound onto a second reel bar supported on the rails. As the paper on the second wound reel bar reaches a full or wound condition, rotation of the new reel bar is started to bring the new reel bar up to a speed that will allow it to receive the paper web. The new reel bar is then lowered into nip driving engagement with the driving drum and the paper is cut so that the paper now winds onto the new reel bar. This initial winding position for the new reel bar is referred to as the primary winding position. The wound second reel bar supported on the rails is referred to as the secondary winding position. The second wound reel bar is then moved down the rails away from the winder, rotation is halted, and the wound second reel bar is removed from the rails.
Next, the new reel bar is moved or rotated about the winding drum from the primary winding position to the secondary winding position. During this rotation, the reel bar is maintained in nip driving engagement with the driving drum by a transfer arm mechanism. Once the reel bar reaches the secondary winding position, the reel bar is usually supported on rails and another arm maintains the reel bar in nip driving engagement with the driving drum. This permits the transfer arm mechanism to release the reel bar and move back to its initial position to receive a new reel bar.
This form of winding with the driving drum contacting the reel bar has a tendency to have an uneven nip pressure over the width of the web. This is usually due to roll deflection. Roll deflection effects the tension of the web wound onto the reel bar and is more severe when the web being reeled is recycled. With environmental concerns, an increased usage of recycled paper has occurred. Recycled paper includes a wide variety of paper products and the incorporation of recycled fiber in newsprint and other paper furnishes.
Accordingly, it is believed that the use of a center wind assist mechanism in the reeling/winding operation will result in a more even winding tension to the reel bar. While center assist winding is known in the art, it is believed that the center assist winding device of the present invention provides a novel structure that results in an even tension being provided to the web wound onto the reel bar when the reel bar is in its primary winding position and moved to its secondary winding position.